Allium Cepa Bulb Extract
Onion bulb extract with quercetin and sulfur compounds. In haircare claimed as a hair-growth stimulator; in creams as anti-inflammatory.
Evidence by route
Topical application
Anti-inflammatory potential described in models. Small studies on scar treatment exist with inconsistent results.
- Draelos ZD. J Cosmet Dermatol. 2008;7(2):101-104. PMID 18482012
How to read tiers A–F
- CWeak evidence. In vitro data, open-label studies, or expert consensus
Tolerability and safety
- Irritation potential
- Medium
- Allergen risk
- Moderate
- Pregnancy
- Safe
- Suitable for
- Normal, Oily, Combination
- Use with caution
- Sensitive, Dry
About this ingredient
Allium Cepa Bulb Extract is an onion bulb extract. Contains quercetin, sulfur compounds (allicin, S-allyl-cysteine), flavonoids. Claimed mechanism. In haircare – stimulates scalp circulation via the irritating and warming effect of sulfur compounds; theoretically promotes hair growth. In creams – anti-inflammatory via NF-κB suppression (quercetin), antibacterial against staphylococci (allicin). Also used topically for hypertrophic and keloid scars. Where applied. Hair-loss shampoos and lotions (1–10%, brands include Mediceuticals, Indola, Spanish Pilexil), scar gels (Mederma, Contractubex – contains onion extract), anti-inflammatory serums. Evidence base. Sharquie 2002 (n=38, 4 weeks, raw onion juice) showed hair regrowth in 87% of patients with alopecia areata vs 13% placebo. Meta-analysis Wu 2020 (n=900) for onion-extract gels on hypertrophic scars showed modest scar volume reduction (SD 0.3). Effect is modest and far from clinically significant compared to minoxidil or intralesional steroids. Safety. CIR confirmed safety at cosmetic concentrations. Contact dermatitis possible in 5–10% of patients due to the irritating effect of sulfur compounds. Strong smell may persist on skin and hair for several hours after application. Pregnancy and lactation – topically safe. Oral onion in pregnancy is also safe and even recommended for flu and colds. Topical use in pregnancy is unrestricted. Realistic take. Modest evidence, weak effect. For alopecia, minoxidil 5% is far more effective. For scars, silicone patches plus intralesional triamcinolone are far more effective. Onion as monotherapy is not first-line in any niche.
Frequently asked questions
Is Allium Cepa Bulb Extract safe during pregnancy?
Allium Cepa Bulb Extract is considered safe during pregnancy at typical cosmetic concentrations. Systemic absorption through the skin is minimal.
What skin types is Allium Cepa Bulb Extract for?
Allium Cepa Bulb Extract suits: normal, oily, combination. Use with caution in: sensitive, dry.
Can Allium Cepa Bulb Extract irritate the skin?
Allium Cepa Bulb Extract has moderate irritation potential. Sensitive skin may show a transient reaction that usually settles with adaptation.
What is Allium Cepa Bulb Extract and what does it do in cosmetics?
Onion bulb extract with quercetin and sulfur compounds.
What's the INCI name for Allium Cepa Bulb Extract?
The INCI name is Allium Cepa Bulb Extract. It may also appear as: Onion Extract.
See Allium Cepa Bulb Extract in a product composition right on the store page
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